Projection lamp holder



Sept. 22, 1953 R. E ULRICH ET AL PROJECTION LAMP HOLDER Filed Nov. 29,1949 MW, 55:75 Z/zz/m' (Itforneg Patented Sept. 22, 1953 PROJECTION LAMPHOLDER Robert E.

Ulrich, Riverton,

and Vesper A.

Schlenker, Camden, N. J., assignors to Radio Corporation of America, acorporation of Delaware Application November 29, 1949, Serial N 0.130,013

6 Claims.

The present invention relates to projection lamp holders, and moreparticularly to a miniature, prefocused, projection lamp holderparticularly useful in sensory aid instruments for the blind.

Many instruments of a type particularly useful to blind persons forproviding information as to the presence of objects in their path dependfor their operation upon a projected beam of light which originates froman accurately located light source. Because of the high degree ofsensitivity of these instruments, the light source should be providedwith a support or holder which will secure it against movement from itsposition in the instrument regardless of any movements of the instrumentor vibrations transmitted thereto during the carrying of the instrument.Propection lamps for these indicating instruments are generally quitesmall, and in many cases are of the order of approximately one half ofan inch in length and one eighth of an inch in diameter. Because of thissmall size, considerable difiiculty is encountered in assembling such alamp in an instrument and rigidly securing it against further movement.Conventional, prefocused lamps and their holders in use today have notbeen found satisfactory, particularly for blind aid instruments, eitherbecause the lamp is not firmly secured in position to project a beam oflight without deviation from a definite axis, or because readjustmentsofthe position of the lamp are necessary with each replacement of thebulb. In addition thereto, the prior art lamp holders known to us havenot been of such design that a blind person, who must rely only on hissense of touch, can replace the bulb easily and accurately.

It is, therefore, the primary object of our present invention to providea projection lamp holder whereby the lamp filament will be accuratelylocated and secured in a fixed position at all times to project a beamof light uniformly along a predetermined axis.

It is another object of our present invention to provide a projectionlamp holder for a sensory aid instrument for the blind which permitsquick and easy removal of the lamp from its holder and accuratereplacement thereof without further focusing adjustments beingnecessary.

It is still another object of our present invention to provide aprojection lamp holder for It is also an object of our present inventionto 2 provide a projection lamp holder which is simple and easy toconstruct and which requires no special skill to effect accuratelocation of the lamp within an instrument in the event replacementthereof is necessary.

In accordance with our present invention, we provide a projection lampholder comprising a tubular retaining member which is open at both ends,and a cylindrical housing closely fitting around and providing a lightshield for an electric projection lamp, the housing being removablycarried Within the tubular retaining member. Both the retaining memberand the lamp housing are provided with at least one aperture in theirrespective sides for the emission of light therethrough with the lamphousing aperture being disposed opposite to the lamp filament. The lamphousing, which is dimensioned to be slidably mounted within theretaining member, is provided with a pin extending through the housingfor cooperation with a locking slot in the retaining member, the pin andslot also serving as orienting means for aligning the apertures. Oneportion of the pin member is arranged to receive a tool to facilitateremoval and replacement of the lamp and its housing from the retainingmember. The housing is of greater length than the lamp and the retainingmember is substantially as long as, or longer than, the housing so thatthe lamp and its housing are secured against movement in the retainerthroughout a major portion of the length thereof, A supporting member,which is suitably mounted in the instrument, is provided fortheretaining member and is adjustable in different directions in two planesdisposed normal to each other topermit accurate positioning of the lampfilament.

The novel-features characteristic of our invention, as well asadditional objects and advantages thereof, will be better understoodfrom the following detailed description when read in connection with theaccompanying drawing in which,

Figure l is a perspective view of a projection lamp holder in accordancewith our present invention, together with an adjustable supporttherefore and shown in association with a lens and contact member,

Figure 2 is an enlarged, side View of the electric lamp and housingtherefor, a portion of the extraction tool being shown broken away, andFigure 3 is a central, longitudinal section of the projection lampholder shown in Figure 1 the extraction tool being shown in elevation.Referring more'particularly to the drawing,

wherein similar reference characters designate corresponding partsthroughout, there is shown a projection lamp holder l comprising anelongated, hollow cylindrical retainer 3 which is open at both ends, andan electric lamp assembly 5 comprising an electric lamp or bulbl mountedin a. housing 9 comprising a hollow, cylindrical, opaque shield orsleeve member which is received telescopically in the retainer 3.

The electric lamp assembly 5 has an outer diameter of slightly smallerdimension than the inner diameter of the retainer 3 so as to be freelyslidable therein. The end H of :the retainer 3 is outwardly flanged tofacilitate inserting the lamp assembly 5 within the retainer 8and'f-unctions as a guide therefor. A pin i3 extends laterally throughthe housing pr shield member 1,9 adjacent an open end It thereof and hasan end portion ll extending outwardly from the shield member 8. Theretainer 8 is provided with a locking, J-shaped slot '19 starting at theflanged end ii and extending longitudinally inwardly from the peripheraledge thereof. The slot it is dimensioned to slidab-l-y receive the pinl3 and lock the lamp assembly l5 securely in the retainer 3 when the pinis is disposed in the innermost position at the end 21 of the slot, asshown particularlyin Figure 1 of the drawing. The shield member '8 is ofgreater length than the bulb Ti, and the retainer '3 is of a length atleast as great as, and preferably of greater length than, the shieldmember -9 so that, when the shield member 9 is disposed within theretainer 3 and the pin i3 is in the locked position in the slot Is, thretainer will support the shield member .9 throughout the greatestportion or its length.

Another portion 23 of the pin ["3 extends diametrically across theinterior of the shield member 9 and is dimensioned .to receive a tool 25which has a bifurcated end 2''! and may :be inserted through the shieldmember open end 15. The bifurcated end 21 of the tool member .25 isbiased to frictional-1y hold the pin portion 23 between the end portionsthereof .so that, when the lamp assembly 5 is inserted into the retainer3, it can be locked readily in the slot [9. After the lamp assembly :hasbeen locked in position in the retainer 3, the tool member 215 may .beremoved easily by pulling 'it longitudinally outwardl-y from the shield:member 9, a handle '29 being provided in the opposite end of the toolmember to facilitate application of the :toolmemher to the pin 18 ormounting the lamp assemply-5 in the retainer 3.

The electric lamp or bulb 11 is provided :witha filament 3i and a pairof wire leads '33, .35 connected to the filament and extending outwardlyfrom one end of the bulb l. The bulb "TI is mounted inside the shieldmember 9 with the sides of the bulb in closely spaced relation to theinternal wall of the shield member 9 and at a predetermined distancefrom the pin E3. The bulb is securely held in place in the shield memher9, as by cement 31 shown in Figure 3 of the drawing, so that thefilament 3i will be disposed at all times in an accurate, prefocusedposition when mountedinan instrument.

A pair of diametrically disposed apertures '39 is provided in the sideof the shield member -9- Opposite the filament 3i and in registrytherewith for the purpose of passing light through the shield member '9,and another aperture 4| is provided in the retainer 3 for the ,samepurpose. The apertures 39, .4I are so d sposed the sides of theirrespective members 9,. '3 that,

when the lamp assembly 5 is mounted within the retainer 3, the apertures39, 4| are in alignment and the electric bulb 1 will cast a beam oflight along an axis such as that represented by the broken line @3 inFigure 1 of the drawing. The lamp axis ll? may be so arranged that whenthe lamp and its holder are mounted in an instrument (not shown) fixedlysupporting a lens at such as the lens pictured in the drawing, the lampwill project a beam of light (not shown) through the lens id. While twoapertures 39 are shown provided in the shield member 9, only one ofthese apertures is necessary to project the beam of light through thelens M. The other aperture *has been found advantageous in assemblingthe bulb l in the shield member 9 and reflecting the proper preiocusingof the lamp filament 3! and orientation thereof with respect to the pinit during manufacture of the assembly.

A source of energy (not shown) for making electrical connections to thefilament lead wires 33, 1555 may .be provided in any suitable manner.However, as shown in the drawing, the retainer 3 and shield member .aremade from metal .in order to serve as one of the contact .elements forthe "bulb filament El with .one of the lead wires being attached to theshield member 3. The other contact element comprises a button 55 mountedin the end Ill .of the shield member 9 opposite the .end containing thepin it and the other lead wire 35 is connected thereto. The button 435secured in place by a suitable insulating'rnaterial 59 and is arranged.to engage a resilient contact member .5! mounted on a .wall .of theinstrum nt housing in which the holder is mounted. The button attachedto oneend of f lament wire and a contact element, including the shieldmember .9, and the retainer 3,-attached to filament wire Figures 1 and2, perform th function of lighting the lamp by completing the electricalconnection between the scurceoi energy (notshown) and the lamp filamentill A suitable support or jholder 5.5 is provided for the retainer 3,the retainer being secured to the holder .by force fitting .or in anyother suitable manner. The support is .adjustably supported from awalled structure within the instrument with which the lamp holder 1 isassociated and is adjustable in different directions in two planesnormal to each other, and another :plane pass.- ing through the 'lensaxis 53. For this purpose, adjusting screws .5? :or other suitableadjusting means are provided which are threaded through the walledstructure.

Thus, it will become obvious to those persons skilled in the art, thatwe have provided a projection lamp holder i which is particularlyadapted :for use in instruments for blind people. The holder i is notonly simple in construction but permits an unskilled person to replace alamp in the instrument without further adjustments being necessary afterthe lamp is "locked in its retainer in the instrument. Furthermore, thearrangement of interlocking .of parts makes it impossible for anyone toincorrectly replace a ulb.

While we have described and illustrated but a single embodiment of ourpresent invention, it will also be recognized that various changes andmodifications are possible within the spirit of our invention.Therefore, we desire that 13161 341- ticular form of our inventiondescribed herein shall be considered as illustrative and not aslimiting.

What is claimed is:

1. In a projection lamp holder, the combination of a retainer having acylindrical inner surface and an aperture in a side thereof for thetransmission. of light, an electric bulb having a filament therein, anda housing for said bulb, said housing being slidably mounted within saidretainer and having an opening in a side thereof for the transmission oflight, said bulb being mounted within and held by said housing with saidfilament disposed opposite to and in registry with said housing opening,cooperative means on said retainer and said housing for locking saidhousing and said bulb in fixed position within said retainer, said meansbeing oriented with respect to both said openings in a manner to alignsaid openings one with the other, and said housing being so disposedWithin said retainer that said retainer supports said housing throughoutat least a major portion of its length.

2. An electric lamp assembly adapted for slidable mounting in a hollow,cylindrical retainer having an aperture and also having locking meanstherein, said lamp assembly comprising a sealed bulb having a filamentmounted therein and a pair of leads connected to said filament extendingoutwardly from said bulb, an elongated opaque, sleeve encompassing saidbulb and being at least coextensive with said bulb and constituting alight shield therefor, said sleeve having at least one aperture disposedin a side thereof adjacent to said filament for providing a lightchannel therethrough, electrical contact means disposed in one end ofsaid sleeve and connected to one of said leads, and means disposedadjacent to the opposite end of said sleeve for cooperation with saidlocking means for looking said lam assembly in the retainer.

3. A projection lamp holder comprising an elongated, hollow, cylindricalretainer having at least one end open, a hollow cylindrical shieldmember telescopically mounted in said cylindrical retainer, said shieldmember having an open end and an electric lamphaving a filament, saidlamp being mounted within and held by said shield member, saidcylindrical retainer and said shield member each having at least oneaperture in their respective cylindrical surfaces, said shield memberaperture being disposed adjacent to and in registry with said filament,and said cylindrical retainer in said shield member being provided withinterengageable means for effecting and maintaining said apertures inalignment, said interengageable means comprising a pin disposed adjacentto one end of said shield member and having an end portion extendingoutwardly therefrom, said pin having another portion thereof extendingdiametrically across the hollow interior of said shield member, theportion of said pin disposed within said shield member being positionedto receive a tool member inserted through said shield member open end tofacilie tate replacement of said shield member and said electric lampwithin said cylindrical retainer, and a locking slot disposed in one endof said cylindrical retainer extending longitudinally inwardly from saidone end and dimensioned to slidably receive said first named pin endportion.

4. A projecting lamp holder comprising an elongated, hollow, cylindricalretainer having at least one end open, a hollow cylindrical shieldmember telescopically mounted in said cylindrical retainer, and anelectric lamp havin a filament, said lamp being mounted within and heldby said shield member, said cylindrical retainer and said shield membereach having at least one aperture in their respective cylindricalsurfaces, said cylindrical retainer and said shield member compriseelectrical conducting members, said shield member being provided with anelectrically conductive contact button mounted in one end thereof andinsulated from. said shield member, and said lamp being provided with. apair of leads connected to said filament and ex tending to the exteriorof said lamp, one of said leads being connected to said shield memberand the other of said leads being connected to said contact button, saidshield member aperture being disposed adjacent to and in registry withsaid fi ament, and said cylindrical retainer and said member beingprovided with interengageable means for effectin and maintaining saidapertures in alignment.

5. A projection lam holder comprising an elongated, hollow, cylindricalretainer having at least one end open, a hollow cylindrical shieldmember telescopically mounted in said cylindrical retainer, saidprojecting lamp holder being provided with support means engaging saidcylindrical retainer, and wherein said support means is provided withadjustable means for adjusting said support means and said lamp holderin separate planes normal to each other, and an electric lam having afilament, said lamp being mounted within and held by said shield member,said cylindrical retainer and said shield member each having at leastone aperture in their respective cylindrical surfaces, said shieldmember aperture bein disposed adjacent to and in registry with saidfilament, and said cylindrical retainer and said shield member beingprovided with interengageable means for efiecting and maintaining saidapertures in alignment.

, 6. An electric lamp assembly adapted for slidable mounting in ahollow, cylindrical retainer having locking means therein, said lampassembly comprising a sealed bulb having a filament mounted therein anda pair of leads connected to said filament extending outwardly from saidbulb, an elongated opaque, sleeve encompassing said bulb and being atleast coextensive with said bulb and constituting a light shieldtherefor, said sleeve having at least one aperture disposed in a sidethereof adjacent to said filament for providing a light channeltherethrough, electrical contact means disposed in one end of saidsleeve and connected to one of said leads, and means comprising a pinextending laterally through. said sleeve, a portion of said pin Withinthe interior of said sleeve being positioned to receive a tool insertedthrough said opposite end of said sleeve to facilitate replacement ofsaid lamp assembly in the retainer.

ROBERT E. ULRICH. VESPER A. SCI-ILENKEB.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 953,425 Miller Mar. 29, 1910 1,180,658 Kratz Apr. 25, 19161,199,731 Ilgner Sept. 26, 1916 1,921,214 Carpenter Aug. 8, 19332,088,559 Kollsman July 27, 1937 2,171,431 Kollsman Aug. 29, 1939FOREIGN PATENTS Number Country Date 607,338 Germany Dec. 21, 1934

